The 9-1-1 call is chilling: A woman, who has locked herself in a room after enduring a severe beating, screams. Then she screams again and again. If there are words, they are unintelligible, but terror can be conveyed without words.

Metro Police Detective Chris Baughman played the tape at a human trafficking conference at UNLV on Saturday to illustrate the brutality of the pimps he investigates.

The pimp had beaten the woman with a baseball bat. Baughman showed pictures of the bat, now damaged from hitting human bone. The victim, whose identity was concealed, had archipelagos of yellow and purple bruising on her face, thighs, torso and breasts.

Saturday’s conference was instructive about the other side, the pimps who keep all the money the women make. It’s not clear what percentage of prostitutes have pimps, but Metro Police and Alexis Kennedy, a UNLV forensic psychologist who is an expert in human trafficking, say it’s a significant portion. In other words, many prostitutes are not freely engaging in a consensual money-for-sex arrangement — they are held captive, often with violence and the threat of violence.

Kennedy says more research is needed, but notes an intriguing area of inquiry in the relationship between pimps and psychopathy.

Psychopaths can be outwardly glib or charismatic, but are in fact deeply manipulative. They feel no empathy or remorse and avoid responsibility. They can be aggressive and violent and are often pathological liars.

This would seem to fit perfectly many of the pimps Baughman describes, including in his book, “Off the Street.”

Kennedy said pimps look for a particular type of woman, especially minors, hundreds of whom she’s interviewed. They are often vulnerable, perhaps having faced sexual assault. Baughman, by contrast, says victims he works with, who are not minors, often come from strong families and include women who have graduated from high school and may be in college.

Once lured in, often with notions of romantic love, pimps use all manner of psychological manipulation, including humiliation, drugs and hopelessness. All of this, Kennedy says, helps instill something akin to “Stockholm Syndrome” — when a captive forms a bond with the captor as a survival mechanism.

When the effectiveness of psychological manipulation wanes, the pimp might resort to violence.

Kennedy draws similarities between a trafficked person and a woman who is a victim of domestic violence. Sure enough, a key challenge for Baughman is getting women to testify against their pimps.

What can we do? The first thing is to raise our voices against the wink-and-nod portrayals of pimps and prostitutes in popular culture. Surely we wouldn’t stand for casual glamorization of domestic violence in songs or movies, would we? I’m not trying to be Sen. Joe Lieberman here, and I love the outlaw ethos of American cinema. But on the way out the door to a “pimps and prostitutes” party, maybe ask yourself if you’d ever go to a “domestic violence” party.

We can also educate legislators so they’ll toughen our statutes governing “pandering,” which is the legal term for pimping. Baughman says the toughest sentence he can get is four years, five if there’s violence. But he says that pimps sometimes only get probation, especially if the women are afraid or unwilling to testify. Just five years for violently enslaving another human being? Also, pimps should be classified as sex offenders and forced to register as such once released. If we’re worried about the prison costs, we should reduce the sentences of nonviolent drug offenders.

Finally, we need more services for women who want to escape and a safe place for them once they do.

Baughman closes his presentation with a more satisfying phone recording, this one a collect call from a pimp locked up in the county jail. His assets have just been seized by police.

Told that his safe deposit box is empty except for the warrant, he’s dejected and responds, “And the money was gone? The money was gone? My life is over. My life is o-v-e-r.”